Having problem with molar #19 for several months (see previous posts.) X-rays, tests, exams all normal. Based on symptoms my gut feeling is there is an internal crack . A root canal and cap would fix it but I first want proof that there is a crack ( I shutter at the thought of a difficult and expensive procedure that doesn't fix my problem!) I've been told that an x-ray cannot detect a crack. Really? I thought that's exactly what x-rays were for! Can another imaging method detect it? (ultrasound, MRI, sound waves, thermal scan???) Has anyone ever confirmed a crack before proceeding with a root canal? What were your symptoms and how did you confirm? Thanks for any replies.